At the expense of signal to noise ratio (SNR), current MEMS accelerometers employ reference electrodes to reduce offset that arises from exogenous mechanical sources. These undesired exogenous sources, like thermal loads, packaging, fabrication, impact, are external loads and typically cause the accelerometer to deform which in-turn causes false acceleration outputs. These undesired exogenous sources have very different dynamics than the acceleration sensing. The acceleration sensing electrodes typically utilize a large, full scale range and move at a high speed. In comparison, the reference electrodes typically have much smaller, full scale range and move at a relatively lower speed. Currently, the reference electrodes are the same size as the acceleration electrodes.
Current designs for accelerometers require offset canceling. Offset paddles (reference electrodes) typically help removed offset caused from package stress. Active electrodes, used for sensing acceleration, are typically the same size as the offset paddles and the offset paddles takes up valuable space and are typically placed some distance away from the active electrodes. Typically, these devices calibrate offset only. Accordingly, devices that provide for self-adjusting calibration of offset and sensitivity are desired.